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Interfacial Electrical Studios on Adhesion of Hematite Particles to Polyester Fabric and their Removal from the Fabric(Part 2) (Polyester 직물에의 Hematite 입자의 부착과 제거에 관한 계면 전기적고찰 (제2보))

  • 강인숙;김성련
    • Journal of the Korean Society of Clothing and Textiles
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    • v.19 no.5
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    • pp.765-773
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    • 1995
  • Effect of interfacial electrical conditions such as, the f potential of PET fiber and u-Fe203 particles, the stability parameter and potential energy of interaction on adhesion of a-Fe903 particles to PET fabric and their removal from the fabric, were investigated as functions of pH, electrolyte and ionic strength. The stability parameter, potential energy of interaction between a-Fe2O3 particles and PET fabric were calculated by using the heterocoagulation theory for a sphere-plate model The adhesion of a-Fe2O3 particles to PET fabric and their removal from PET fabric were carried out by using water bath shaker and Terg-O-Tometer under various solution conditions. The adhesion of a-Fe2O3 particles to the PET fabric and the removal of a-Fe2O3 particles from the PET fabric were biphasic and were maximum and minimum at pH 7~8, respectively. With high pH and polyanion electrolytes in solution, the adhesion of a-Fe2O3 particles to the PET fabric was low but effects of electrolytes on the removal of a-Fe2O3 particles from the PET fabric was small. The adhesion of a-Fe2O3 particles to the PET fabric and the removal of a-Fe2O3 Particles from the PET fabric were biphasic, and were lowest and highest at the ionic strength 1$\times$10-3, respectively. The adhesion of a-Fe2O3 particles to PET fabric was well related with the interfacial electrical conditions; it was negatively correlated with the f potentials of a-Fe2O3 Particles of its absolute value, the stability parameter and the maximum of total potential energy, while, the adhesion was not related with the t potentials of PET fiber itself. Therefore, the primary factor determining the adhesion of a-Fe203 particles to PET fabric may be the stability of dispersed particles caused by the electrical repulsion of particles. The removal of a-Fe203 particles from PET fabric was not related to such interfacial electrical conditions as the t potentials of PET fiber, the stability parameter and the maximum of total potential energy but removal was related to t potential of a-Fe203 particles.

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Effects of Obesity Stress and Health Belief on Weight Control Behavior among Nursing Students (간호대학생의 비만스트레스와 건강신념이 체중조절행위에 미치는 영향)

  • Ham, Mi-Young;Lim, So-Hee
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.11
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    • pp.459-468
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    • 2017
  • This study investigated the factors influencing how obesity stress and health belief impact weight control behavior among nursing students. Data were collected from nursing students in U city between September 1 and October 10, 2016 and analyzed using descriptive statistics, t-test, ANOVA, Pearson's correlation coefficient, and hierarchical multiple regression. Among the general characteristics of the subjects, gender (t=2.30, p=0.044) and health status (F=8.03, p<0.001) significantly influenced weight control behavior. There were negative correlations between diet therapy of weight control behavior (r=-0.26, p<0.001), exercise therapy (r=-0.25, p<0.001), behavior modification therapy (r=-0.29, p<0.001), and perceived barriers in health belief. In addition, acquiring special knowledge for weight control behavior showed positive correlations in obesity stress (r=0.42, p<0.001), perceived susceptibility (r=0.25, p<0.001) and perceived benefits (r=0.19, p<0.001). Furthermore, the significant factors influencing weight control behavior were perceived barriers (${\beta}=-0.30$, p<0.001) and obesity stress (${\beta}=0.20$, p<0.05) in health belief, and these factors explained 17.2% of the variance. Based on the study results, it is necessary to develop and apply effective educational programs that can influence weight control behavior through gender, health status, obesity stress and health beliefs, which determine weight control behavior of nursing students.

Holdup Characteristics of Three Functional Regions in a Slurry Bubble Column (삼상 슬러리 기포탑의 세 기능영역 체류량 특성)

  • Jang, Ji Hwa;Lim, Dae Ho;Kang, Yong;Jun, Ki Won
    • Korean Chemical Engineering Research
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    • v.48 no.3
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    • pp.359-364
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    • 2010
  • Three kinds of functional regions such as continuous slurry(${\varepsilon}_f$), bubble(${\varepsilon}_b$) and wake(${\varepsilon}_w$) regions were identified, and the individual phase holdups of each functional region were determined in a three-phase slurry bubble column of 0.152 m ID. The holdups of bubble and wake were measured by adopting the electrical resistivity probe method. Effects of gas velocity and solid concentration in the slurry phase on the individual holdups of functional regions in the column were discussed. The holdup of continuous slurry phase decreased but that of bubble or wake increased, with an increase in the gas velocity in the column. The increase of solid content in the slurry phase could lead to the increase in the holdup of continuous slurry phase but decrease in the bubble or wake holdup. The portion of wake holdup was in the range of 15~40% of the bubble holdup, which decreased with increasing gas velocity or solid content in the slurry phase. The individual holdups of three functional regions were well correlated with operating variables within this experimental conditions.

The relationship between the character, interpersonal relations, and adjustment to a college life of nursing students (간호대학생의 인성, 대인관계, 대학생활 적응과의 관계)

  • Sim, Sunsook;Bang, Miran
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.12
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    • pp.634-642
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    • 2016
  • This research investigated the relationship among character, interpersonal relations, and adjustment to college life of university nursing students as well as to identify the factors that affect college life. A self-report type survey was conducted on a total of 180 nursing students in a city between May 30 and Jun 09 of 2016. According to our findings, the relationship between the adjustment to school life and character (r=.506, p<.001) as well as between the adjustment to school life and personal relations (r=.585, p<.001) showed a significantly positive correlation in the medium level. With improved personal relationships and with higher level of character, nursing students appear to more successfully adjust to college life. It was also found that an explanatory power for the adjustment to college life of these factors is 46% (F=75.28, p<.001). The study results indicate that it is necessary to develop a program that can improve interpersonal relationships and character of nursing students in order to enhance the adjustment process to college life.

Plant Community Structure of Haneoryoung~Daetjae Ridge, the Baekdudaegan Mountains (백두대간 한의령에서 댓재구간 마루금의 식물군집구조 특성)

  • Cho, Hyun-Seo;Lee, Soo-Dong
    • Korean Journal of Environment and Ecology
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    • v.27 no.6
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    • pp.733-744
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    • 2013
  • This study was launched in order to collect basic data such as emergent species, a succession trend based on the actual vegetation at the ridge from Haneoryoung to Daetjae, thereby designating 46 quadrats($10m{\times}10m:100m^2$). As a result of classification by TWINSPAN, the plant community was categorized into eight different communities, such as Pinus densiflora-Quercus mongolica-Fraxinus rhynchophylla, P. densiflora-Q. mongolica, Ulmus davidiana var. japonica, Q. mongolica-Deciduous Broad-leaved, Q. mongolica, Q. mongolica-Betula davurica, Q. mongolica-F. sieboldiana, and Larix kaempferi. An analyzation of each communities indicated that P. densiflora dominant community will change into a Q. mongolica dominant community if there are no outside artificial disturbances. U. davidiana var. japonica community maintains its present condition, because it doesn't appear to be a competitive species. In the case of Q. mongolica dominant community, if nothing comes in a competitive species against Q. monglica, it is possible to succeed to a muture stand. These communities with competitive species such as F. rhynchophylla, B. davurica that do not emerge at a canopy layer will gradually progress to the Deciduous Broad-leaved community. With regard to the species diversity index per unit ($400m^2$), succession processing communities (P. densiflora: 1.0477~1.1283) tend to be higher than succession-processed communities (Q. mongolica dominant: 0.6446~0.9424).

A Study on the Waste Treatment from a Nuclear Fuel Powder Conversion Plant (핵연료 분말제조 공정에서 발생하는 폐액의 처리에 관한 연구)

  • Jeong, Kyung-Chai;Kim, Tae-Joon;Choi, Jong-Hyun;Park, Jin-Ho;Hwang, Seong-Tae
    • Applied Chemistry for Engineering
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    • v.7 no.6
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    • pp.1164-1173
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    • 1996
  • Treating methods and characteristics of waste from a nuclear fuel powder conversion plant were studied. To recovery or treat a trace uranium in liquid waste, the ammonium uranyl carbonate(AUC) filtrate must be heated for $CO_2$ expelling, essentially. Uranium content of final treated waste solution from fuel powder processes for a heavy water reactor(HWR) could be lowered to 1 ppm by the lime treatment after the ammonium di-uranate(ADU) precipitation by simple heating. Otherwise, in case of the waste from fuel powder processes for a pressurized light water reactor(PWR), it is result in 0.8 ppm as a form of uranium peroxide such as $UO_4{\cdot}2NH_4F$ compounds. Optimum condition was found at $101^{\circ}C$ by the simple heating method in case of HWR powder process waste. And in case of PWR powder process waste, optimum condition could be obtained by precipitating with adding hydrogen peroxide and adjusting at pH 9.5 with ammonia gas at $60^{\circ}C$ after heating the waste In order to expelling $CO_2$. As the characteristics of recovered uranium compounds, median particle size of ADU was increased with pH increasing in case of HWP waste. Also, in case of uranium proxide compound recovered from PWR waste, the property of $U_3O_8$ power obtained after thermal treatment in air atmosphere was similar to that of the powder prepared from AUC conversion plant.

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Decomposition of Rice Straw and Compost in an Acid Sulfate Soil under Aerobic and Anaerobic Conditions (특이산성토양(特異酸性土壤)에 있어서 볏짚 및 퇴비(堆肥)의 분해(分解)에 관(關)한 연구(硏究))

  • Lee, Sang Kyu;Yoo, Ick Dong;Parr, James F.
    • Korean Journal of Soil Science and Fertilizer
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    • v.8 no.4
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    • pp.171-176
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    • 1975
  • The rate and extent of decomposition of rice straw and compost in an acid sulfate soil amended with urea and lime and incubated under aerobic and anaerobic(flooded) conditions were investigated in the laboratory. Results are summarized as follows: 1. The rate of compost(alone) decomposition in a flooded soil was more than twice as high as all other treatments, which included rice straw+urea, rice straw+lime, rice straw (alone), and compost+lime. Lime appeared to suppress the decomposition of compost in a flooded soil but actually enhanced its decomposition under aerobic conditions. 2. Compost decomposition in both anaerobic and aerobic environments was characterized by single maximum peak rates of $CO_2$ evolution that were reached soon after the start of incubation. 3. Both urea and lime greatly increased the rate and extent of rice straw decomposition in the soil when incubated aerobically, although urea had a greater effect than did liming. Decomposition rates were characterized by the appearance of two maximum peak rates, a greater primary peak and a smaller secondary peak. 4. The percent decomposition of rice straw in soil incubated aerobically was approximately half (10.8%) that of compost(23.1%). However, percent decomposition of these substrates in soil amended with lime was essentially the same; i.e., rice straw+lime (29.4%) and compost+lime(31.6%). 5. There is a need to investigate the possible interaction between the addition of lime (pH) and supplemental nitrogen applied to acid sulfate soils and how this interaction might affect the decomposition of organic wastes and residues.

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A Study on Enzymatic Degummings of Raw Silk and Silk Fabric (견의 효소 정련에 관한 연구)

  • Lee, Yong-U;Song, Gi-Won;Jeong, In-Mo
    • Journal of Sericultural and Entomological Science
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    • v.28 no.1
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    • pp.66-71
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    • 1986
  • The studies were carried out to screen the optimum conditions for enzymatic degumming of raw silk yarn and silk fabric by use of Alkalase, a protease produced by Bacteria, comparing with Papain and Trypsin representing natural proteolytic enzymes. 1. The optimum temperature and acidity of degumming solution were 70$^{\circ}C$, pH 5-6 for Papain degumming, 40$^{\circ}C$, pH 8 for Trypsin and 50-60$^{\circ}C$ pH 8-9 for Alkalase. 2. By increasing the Alkalase concentration in the range of 0.6 to 1.0 gram per liter, the time for enzymatic degumming of silk yarn could be reduced by 40 minutes. 3. In degumming of silk yarn by Alkalase, the pretreatment of 95$^{\circ}C$, 10 minutes at 0.1% sodium bicarbonate solution or posttreatent of 80$^{\circ}C$, 20 minutes at 2% (o.w.f.) sodium silicate solution improved the efficiency of enzymatic degumming, as compared to that of nontreatment. 4. The breaking strength, elongation and Lousiness results of enzymatically degummed silk yarn were apt to be improved more than those of soap-degummed one. 5. When the pretreatment of alkaline solution was done with over 20% of degumming ratio, the enzymatic degumming efficiency of both Havutae and Crepe de chine could be reached to the same level with those of soap-soda degummed. 6. As the pretreated silk fabric with 20% of degumming ratio was under action of three proteases, respectively, the deumming efficiency of Havutae and Crepe de chine were completed by Alkalase more than by Papain or Trpysin. 7. The stiffness of enzymatically degummed Crepe de chine was not only reduced by 17% more than that of soap-soda degummed one but also the Drape coefficient was decreased in enzymatically degummed fabrics, which was closely related with the soft touch of degummed fabrics.

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Effect of Female College Students' Perception of Dating Violence on Sexual Assertiveness : Mediating Effect of Dating Violence Acceptability (여대생의 데이트폭력 인식이 성적 자기주장에 미치는 영향: 데이트폭력 허용도의 매개효과)

  • Koo, Sang-Mee;Oh, Eun-Young
    • Journal of Convergence for Information Technology
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    • v.11 no.12
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    • pp.158-167
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    • 2021
  • This study was attempted to investigate the mediating effect of the tolerance of dating violence in the influence of female college students' perception of dating violence on their sexual self-assertion. The subjects of this study were 161 female students enrolled in universities in the Chungbuk region. As research instrument, Jeong(2013)'s perception of dating violence, Jeong(2016)'s sexual self-assertiveness, and Nam(2003)'s dating violence acceptability were used. For data analysis, frequency, percentage, correlation analysis, hierarchical regression analysis, and Sobel test were performed using SPSS WIN 21.0 program. As a result of the study, first, there was a significant positive correlation between perception of dating violence and violence tolerance(r=.43, p<.001), and a significant negative correlation between violence tolerance and sexual assertiveness(r=-.20, p<.05). Second, the perception of dating violence had a significant positive effect on sexual assertiveness(𝛽=.43, p<.001), and the explanatory power was 19%(F=36.10, p<.001). Third, it was found that the decrease in the effect of female college students' perception of dating violence on sexual assertiveness was significant(Z=2.05, p<.05), violence acceptability showed a mediating effect on the effect of dating violence perception on sexual assertiveness. Based on this study, it is suggested to develop a dating violence prevention program that can lower female college students' acceptability for violence, raise perception of violence, and strengthen sexual assertiveness.

The Relationship Between Risk Perception, Knowledge, Risk Attitude, and Health promoting Behavior for Fine Dust in Nursing College Students (간호대학생의 미세먼지에 대한 위험인식, 지식, 위험태도, 건강관리행위 간의 관계)

  • Koo, Sang-Mee;Kim, Hyun-Ji
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.7
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    • pp.78-84
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    • 2019
  • The purpose of this study is to investigate the relationship between risk perception, knowledge, risk attitude, and health promoting behaviors of nursing college students. The data were collected from 168 university students of four-year nursing college in the city of D, C. The collected data were analyzed by independent t-test, one way ANOVA and Pearson correlation coefficient using SPSS WIN 20.0 program. As a result this study knowledge of fine dust was statistically significant in respiratory disease(t=1.92, p<.001). The risk attitude toward fine dust was statistically significant in respiratory diseases(t=2.05 p=.042), subjective health status(F=3.79, p = .012). There was a significant positive correlation between risk perception of fine dust and knowledge(r=.340, p<.001), risk attitude(r=.492, p<.001), and health promoting behaviors(r=.354, p<.001). Knowledge of fine dust and risk attitude(r=.401, p<.001), health promoting behavior(r=.296, p<.001), risk attitude toward fine dust and health care behaviors(r=.550, p<.001) also showed a statistically significant positive correlation. Based on these results, it will be necessary to develop a program to improve awareness and knowledge of fine dusts in nursing college students and to improve health promoting behaviors.